CX500 GL500 650 Global

Hello fellow cx'ers

A little background on my 78:

1. The bike does not smoke when cold or upon first starting (rules out leaky valves, i think)
2. The bike will foul out the left plug after it gets hot, the right plug does not get oil fouled.
3. The bike will smoke pretty bad after it gets hot.

I have a serious problem with my bike smoking (what I think is burning oil) at warmer temps and during throttle acceleration. I have done a compression test last night and have 160 in left and 158 in right cyl. I then add a bit of 10w40 through the spark plug holes to test again, and my gauge shot up to around 270-300.

Can anyone explain this?

I told you when I listened to the video Phil on CC's that I suspect deep engine problems that only an engine strip will resolve.The compression test is normal when you add oil as it seals the rings and stops blow-by thus increasing the compression for a short period.You may have worn valve stem seals/Valve guides but I can hear an engine knock which on these bikes is either a worn cam-chain and possible big-end damage from that.

Shep

Thanks for the info, I plan to address the knocking eventually, but I don't see how this would effect the smoking bit. I'd like to try and resolve the smoking problem before putting any more time into resolving what is causing the noise. I do plan on doing tappets and cam chain adjustment though. Guess I should pull the heads and check the valves.

Check in the Air filter box.Is there a lot of oil in there?

If so clean it all out.Also you can re-use the Air filter so long as it's not fallen apart by soaking in Gas/Petrol in a bucket and then air blowing through.

Sorry Shep, it has pod filters. I posted on CC and will be pulling the heads hopefully this weekend. Whats the best source for replacement gaskets/valves/seals (if needed)?

As you are in the US see the Must Read section on CC's as I think there's the suppliers on there but also a few on here,

viewtopic.php?f=17&t=39

Having had a think about it I stand by my 1st diagnosis.I think the big-end or main bearings are shot and causing crank-case back pressure.This would cause the smoke.